天津城市化对市区气候环境的影响

利用天津市区和郊区两个气象站近50年的地面温度、辐射、日照、风速、相对湿度和降水量资料，系统地分析了天津城市化进程对城市气候的影响，结果表明影响是显著的。受城市化的影响，天津市区地面温度远高于郊区，城市热岛效应明显，市区增温率达0．42℃·（10a）^-1，50年增温幅度达2．5℃，其地面总辐射、直接辐射和日照时数逐年减少的特征也进一步证明了城市化对大气的增温效应；市区近地层风速、相对湿度明显小于郊区，其中，平均风速以0．35m·s^-1·（10a）^-1的速率减小，相对湿度以1．11％·（10a）^-1的速率减小。近50年来天津市区的降水量和降水日数均呈现明显的减少趋势，降水量的倾向率为5．91mm·（10a）^-1，降水13数的倾向率为3．2d·（10a）^-1。

The climate impact of urbanization in Tianjin city

In this paper, the climate impact of urbanization in Tianjin city is analyzed with nearly 50 years observations, such as sur-face temperature, radiation, sunshine, wind speed, relative humidity and precipitation, from two weather stations. Results show the impact is remarkable. Subject to the effects of urbanization, the surface temperature in urban is much higher than suburban. The ur-ban heat island effect is obviously. Urban warming rate is 0.42 degree per ten years, and the increased range of the temperature reach to 2.5 degree in the last 50 years. The warming effect caused by urbanization are further proved by decreasing of surface total radia-tion, direct radiation and sunshine duration; Both the surface layer wind speed and relative humidity in urban, where the decrease rate is 0.3 m·s~(-1) and 1.11% per ten years, are less than that in suburban. In the last 50 years, the precipitation and the days of precipitation decreased significantly, the tendencies are 5.91 mm and 3.2 d per ten years separately.